Abstract 738 Poster Session IV, Tuesday, 5/4 (poster 7)

Background: Colicky infants are commonly thought to suffer disturbed sleep. Some questionnaire based studies had suggested that colic infants have more wakings during night-time, but no objective sleep polygrafically confirmed studies exists.

Objective: To compare night-time sleep structure between colicky and control infants.

Study design: The average cry and sleep time of the infant at one month of age was estimated according to a daily diary filled in by the parents in home for a one-week period. Overnight polygraphic sleep recordings were performed at two months of age (16 colicky infants and 16 control infants) and at 7 months of age (12 colicky infants and 14 control infants) in a sleep laboratory. The proportion of sleep states, amount of stage shifts, number of movements (observed by static-charge-sensitive-bed) and respiratory events were analyzed.

Results: Infants daily crying time was 225 min (SD 69, range 139-390min) in the colic group and 35 min (SD 31, range 0-105) in the control group. The total daily sleep duration was shorter in colicky infants compared to the controls according to diaries at 5 weeks of life (12.8 hours SD 1.5 compared to 14.2 hours SD 1.0, p=0.006). However, the sleep structure was similar in colicky and control infants in both ages in a sleep laboratory. Proportion of sleep stages in colicky and control infants at the age of two months were: REM 27.5% (SD3.4) vs. 27.2% (6.2), "light" NREM (sleep stages 1 and 2) 29.1% (5.2) vs 27.4% (7.4), "deep" NREM (sleep stages 3 and 4) 40.0 (5.2) vs. 41.9% (4.5), number of stage shifts / hour 22.0 (3.2) vs 22.3 (4.2) and at age of 7 months: REM 26.4% (5.1) vs 24.0% (4.2), sleep stage 1 12.9% (2.8) vs 13.7% (3.8), sleep stage 2 36.6% (6.5) vs 37.0 (8.5), sleep stage 3-4 22.5% (5.1) vs 23.8 (6.1) and number of stage shifts / hour 14.3 (2.3) vs 13.5 (2.2). Also there were no differences between study groups in sleep duration, number of arousals, movements or respiratory events in a sleep laboratory.

Conclusion: This study confirmed the previous findings that the total sleep time was shorter in colicky infants than in the control infants according to diaries during colic. However, sleep polygraphy did not reveal any differences between colicky and control infants at 2 or 7 months of age. These findings suggest that infantile colic is not either a consequence or a cause of sleeping disturbance.

This study was funded by Arvo and Lea Ylppo - foundation and Finnish Pediatric Research Foundation